Engine Management Light Flashes after Cambelt Change

[Lionheart]

Hi guys

Bit of a weird one (?)

Just had the cambelt changed by my local garage. They used only genuine Audi parts (I know because I bought and supplied them!)

They had an issue. Basically, there was a setting marked in paint from the last cambelt change (done by Audi!) They set it to the correct settings, which was one tooth forward of this paint mark.

This caused the engine management light to come on and throw up a diagnostic issue that the timing was out. So, they re-stripped it (free of charge!) and set it up incorrectly one tooth out of place to the paint mark.

Seems to have solved it. Except...

Under heavy accelleration between 40mph and 60mph approx then engine mangement light will FLASH for 5-10 seconds and then go off. It's done this twice - once on each of my test drives since collecting the car.

So, I'm going to contact them, and also pop it on Vag Com in a bit - but I wanted to know if anyone here has experienced a similar issue, or might know what could cause this?

It was a bit wet on both test drives. Would four wheel spin make the light flash???? I would think not as that would be traction control! Just racking my brain to come up with ideas!!

It only does it under the heavy accelleration, and is fine at all other times and normal driving.

Any ideas guys???

[mik15]

could be something else not related with the cam belt...Vag Com should make some light! Let us know!

[Daveperc]

Are you sure it's the engine light?? THe ABS light will flash under heavy acceleration if it is breaking traction??

Dave

[bam_bam]

This caused the engine management light to come on and throw up a diagnostic issue that the timing was out. So, they re-stripped it (free of charge!) and set it up incorrectly one tooth out of place to the paint mark.

Seems to have solved it. Except...

I thought it was a special tool used to lock the cam, did they use one?

The traction control light is orange and it will flash under certain accelerating conditions (I'm with Dave on his theory). The TC light is located on the tach side of the binnacle, the engine management light is on the speedo side of the binnacle...

[Lionheart]

Hi there

Yes, definitely the engine light. It's an engine shaped outline in yellow.

Right - I'm going out to pop it on Vag Com now...

[chunky79]

Hmmmm. I had this on an engine where the cam gear had turned on its key way. The engine would start but throw up cam/crank timing fault. Has your engine had any major work done on it? Strange that the timing marks are out.

[Lionheart]

Hi guys!

Ok, to confirm it is definitely the engine management light (in the speedo dial to the left of the pin, yellow outline of engine). It flashes for 5-10 seconds, it does not stay on.

I've run Vag Com on it and it's come up with this:

-------------

Address 01: Engine Labels: 077-907-558-BCY.lbl
Part No: 4D1 907 558
Component: 4.2l V8/5VT G 0004
Coding: 0010752
Shop #: WSC 00000 785 00200
VCID: EBD13F58C9E75240647

5 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 -
16685 - Cylinder 1
P0301 - 002 - Misfire Detected
16688 - Cylinder 4
P0304 - 001 - Misfire Detected
16687 - Cylinder 3
P0303 - 002 - Misfire Detected
16686 - Cylinder 2
P0302 - 002 - Misfire Detected
Readiness: 0000 0000

-------------

So it's not coming up as a timing fault, which it did until they rolled the cambelt back one notch to match the paint mark left by Audi.

No major engine work that I know of!!

I guess misfire is better than timing issues!

When the cambelt was changed they also did a full service for me (again all genuine parts supplied by me).

There were no misfire issues before. Is this likely to be air related, oil related, spark plug related???

The plot thickens...

[chunky79]

Could it be a plug in the loom? Not sure what has to be removed to do the cambelt.

[Lionheart]

I noted it's misfiring on 1/2/3/4 - which is the bank on one side right??

Very unlikely that four coil packs/plugs have packed in at the same time... So - is there something (singular) that controls the four coil packs/cylinders???

[nukinukinuki]

If the problem was never their before it entered the garage…Then just stop trying to diagnose it yourself and take it back to the garage. I wouldn’t even be telling them you have had it diagnosed as a misfire they might think you’ve been messing under the bonnet and caused the problem.. Hence having it diagnosed yourself.
They have obviously created an issue from either incorrect fitment of item(s) or damaged some component during the process... Weather it was during the Cam belt change or Service. It could be something as simple like spark plug Gaps not been checked prior to fitting.
I would personally take it back. Explain what you’re experiencing and give them a chance to rectify the issue. This is what you pay for. The whole reason you take it to a competent garage to ensure the job is done correctly.
If you decide to take this on yourself with little experience of these cars at this stage you will face further costs with lots of guess work and potentially more labour costs going to someone else when you have finished guessing.

[Lionheart]

Hi there

Yes, absolutely! I have already spoken to the garage and they will of course take the car back and rectify the issue. There's no argument there. I've used them for several years on my cars and they're very good guys!

So that side of it is not an issue.

I wanted to get some info from fellow RS6er's so I know myself what likely causes are, so they know at the garage that I know what I'm talking about - which always helps lol! Also help to point them in the right direction too!

I'm also quite fascinated by it, and I'm sure other RS6er's may find this useful both now and in the future.

Any ideas why the four cylinders would all be showing up as misfiring?? One cylinder makes sense, but four? And all on the same side (I beleive?) Must be something logical there somewhere...

[Nobby]

Well, when you say 1 'paint mark' where is it? - on the crank or the cam pulleys?

If its 1 tooth on the crank and if it was not correct then that would affect the timing on both banks . If the timing 'paint mark' was incorrectly set on 1 cam wheel then that would affect the timing on one bank only, hence why the ECU might be detecting a missfire. There are a multitude of things that could have been done wrong, so its very important that the correct locking tools are used. I believe the RS6 kit includes a long setting tool which bolts on the pulleys and keeps them exactly in time at a certain point, then there is a pin to lock the crank in a place. You could also use a DTI gauge & protactor to find exact TDC.

The bottom pulley spins at twice the speed of the cams, therefore if there are 30 teeth on it, the cams have 60 teeth. 1 tooth at the cam pulley is 6deg, 1 tooth at the crank is 12 deg!

Having said that its remarkable what some cars could take in terms of being miss-timed. I changed a friends cambelt on his fiesta after the tensioner fell to bits. The car still ran but sounded horrid, very very loose belt too. Put all the new stuff on and reset the timing and it was perfect again.

[Lionheart]

I just called them to check. They said it was on the crank sproket.

The crank was not locked in place because that's where the paint mark came in. They tried it first off all ignoring the paint mark and doing it 'as it should be done' and that threw up the crank timing issues on dianostics (and engine management light on). So they redid it using the paint mark, but now I'm having this issue on the cyclinders on one side - which I did not have before.

They also said something about a paint mark on the alternator pulley? Admittedly I was not sure what they meant as it got a bit tech-heavy.

[Nobby]

They also said something about a paint mark on the alternator pulley? Admittedly I was not sure what they meant as it got a bit tech-heavy.

And the alternator runs off a seperate belt

[Nobby]

Doing the timing to a fat mark or using the 'screwdriver through the plug hole' simply isn't good enough on a high performance engine.

It may run ok, but you'd be surprised how little movement on the pulley means a big difference in rotation. Similarly there is a big dwell point when the pistons reach top dead centre - so just top isnt good enough.